Rollie Fingers chose to retire from baseball rather than shave off that iconic mustache

The Specialized Bullpen: History, Analysis, and Strategic Models for Success – Society for American Baseball Research

Rollie Fingers Baseball Stats by Baseball Almanac

Major League Beards: Best Beards For Every Position in Pro Baseball - Grooming Lounge

Rollie Fingers: World Series Closer Second to Only One - Cooperstown Cred

Rollie Fingers explains the story behind the mustache - Sports Collectors Digest

Rollie Fingers Baseball Stats by Baseball Almanac

Happy birthday to Rollie Fingers, who chose retirement over shaving his mustache

Happy birthday to Rollie Fingers and his incredible mustache

Rollie Fingers' Mustache Began as a Joke, Then He Chose It Over Baseball